The general problem of geo-location or navigation has been studied for centuries. Prior methods include various forms of dead reckoning, inertial navigation, celestial navigation, and radio-navigation, which are too numerous to list here.
The disadvantages of prior methods for geo-location generally are two-fold: either the methods require access to some form of external aiding signal (man-made or natural, such as global positioning system (GPS) signals or a view of the stars), or they do not provide sufficient accuracy in a small, low-power package. For example, inertial navigation systems are typically large and require significant amounts of power, and they also tend to produce results that drift over time.
Accordingly, there is a need for improved systems and methods that can determine the geographic location of an object without assistance from external radio signals.